Added option for switching languages, changed the translation filter, added Translation service etc.
	modified:   config/exceptions.js
	modified:   config/routes.js
	modified:   controllers/LoginController.js
	modified:   css/bootstrap.css
	modified:   css/mystyle.css
	modified:   directives/CheckPresence.js
	modified:   filters/Translator.js
	new file:   languages/en-us.json
	new file:   languages/sr-rs.json
	modified:   less/mystyle.less
	modified:   manifest.webapp
	modified:   public/app.js
	modified:   services/ExceptionsService.js
	modified:   services/LoginService.js
	new file:   services/TranslationService.js
	modified:   templates/index.html
	modified:   templates/login.html
	modified:   templates/main.html